Comment by reaperducer

Probably a safeguard to keep sonebody from unplugging something during the update.

I can't speak about other cars, but my EV has nothing you can unplug. It's not like a regular car where stuff is exposed.

All it has under the hood is a storage space for charging adapters, a first aid kit, and a cap for the windshield washer fluid.

Even accessing the regular 12V battery takes a bunch of time and tools. The manual states several times that it should never ever be used to jump start another car, though it doesn't explain why.